Generalized Jacobsthal sequence.

Terms

a(0) =1a(1) =1a(2) =3a(3) =2a(4) =11a(5) =21a(6) =22a(7) =85a(8) =171a(9) =170a(10) =683a(11) =1365a(12) =1366a(13) =5461a(14) =10923a(15) =10922a(16) =43691a(17) =87381a(18) =87382a(19) =349525a(20) =699051a(21) =699050a(22) =2796203a(23) =5592405a(24) =5592406a(25) =22369621a(26) =44739243a(27) =44739242a(28) =178956971a(29) =357913941